765521 has 2 divisors, whose sum is σ = 765522. Its totient is φ = 765520.

The previous prime is 765503. The next prime is 765533. The reversal of 765521 is 125567.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 739600 + 25921 = 860^2 + 161^2 .

It is a cyclic number.

It is not a de Polignac number, because 765521 - 2¹⁴ = 749137 is a prime.

It is a Chen prime.

It is a nialpdrome in base 10.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 765521.

It is not a weakly prime, because it can be changed into another prime (765581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 382760 + 382761.

It is an arithmetic number, because the mean of its divisors is an integer number (382761).

2⁷⁶⁵⁵²¹ is an apocalyptic number.

It is an amenable number.

765521 is a deficient number, since it is larger than the sum of its proper divisors (1).

765521 is an equidigital number, since it uses as much as digits as its factorization.

765521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2100, while the sum is 26.

The square root of 765521 is about 874.9405694103. The cubic root of 765521 is about 91.4785003285.

The spelling of 765521 in words is "seven hundred sixty-five thousand, five hundred twenty-one".